The Clinical Core (Core B) component of this PPG will provide the clinical expertise and organization necessary to accomplish the studies involving human subjects that are proposed in the projects within this PPG. The core will be responsible for subject recruitment and communication, clinical specimen collection, subject characterization through clinical data acquisition and subject follow-up. The Clinical Core will interact intimately with the Tissue Processing and Cell Culture Core C to ensure distribution of clinical samples and data to program investigators. In this capacity, the clinical core will function as a collective resource to the PPG that will facilitate accomplishment of each of the three projects and also promote interaction between the different projects to glean the most information from valuable clinical samples. Following recruitment, the core will use a variety of clinical parameters to divide subjects into four well-defined subgroups: 1) nonallergic, non-asthmatic normal volunteers, 2) allergic non-asthmatics, 3) non-allergic asthmatics, and 4) allergic asthmatics. The volunteers will undergo a comprehensive evaluation including pulmonary function testing, allergy skin testing, blood testing and exhaled gas measurements. Select volunteers will also undergo outpatient flexible fiberoptic bronchoscopy. Through this procedure the core will obtain airway specimens including mucosal brushings, bronchoalveolar lavage fluid, and endobronchial biopsy tissue. These specimens will allow the core to assess parameters of airway inflammation and will be further processed by the Tissue Processing and Cell Culture Core C for use by all three PPG projects. For all of the studies within the PPG utilizing human subject samples, the clinical core will be responsible for assuring subject safety, data confidentiality and full regulatory compliance.